U.S. patent application number 13/148815 was filed with the patent office on 2011-12-22 for optical fiber polishing apparatus and method.
This patent application is currently assigned to 3M Innovative Properties Company. Invention is credited to James R. Bylander, Kent E. Lageson, Steven G Lucht, Tomoyasu Oike, Takaya Yamauchi.
Application Number | 20110312249 13/148815 |
Document ID | / |
Family ID | 42740167 |
Filed Date | 2011-12-22 |
United States Patent
Application |
20110312249 |
Kind Code |
A1 |
Bylander; James R. ; et
al. |
December 22, 2011 |
OPTICAL FIBER POLISHING APPARATUS AND METHOD
Abstract
A hand-held polishing apparatus is provided for polishing an
optical fiber connector. The optical fiber connector mounted on the
end of an optical fiber includes a connector housing and a ferrule.
The polishing apparatus includes a connector mount to receive and
hold the optical connector to position the end face of the ferrule
adjacent to a polishing media. The polishing apparatus includes a
housing having an upper portion and a base portion, a drive
assembly and a lubricant dispensing system. The drive assembly
controls orbital movement of the optical connector and linear
movement of the polishing media through the polishing device, and
the lubricant dispensing system supplies a lubricant from an
internal reservoir disposed with in the housing to the polishing
media near the end face of the ferrule of the optical
connector.
Inventors: |
Bylander; James R.; (Austin,
TX) ; Oike; Tomoyasu; (Kanagawa, JP) ;
Yamauchi; Takaya; (Kanagawa, JP) ; Lucht; Steven
G; (Inver Grove Heights, MN) ; Lageson; Kent E.;
(Burnsville, MN) |
Assignee: |
3M Innovative Properties
Company
Saint Paul
MN
|
Family ID: |
42740167 |
Appl. No.: |
13/148815 |
Filed: |
February 22, 2010 |
PCT Filed: |
February 22, 2010 |
PCT NO: |
PCT/US10/24865 |
371 Date: |
August 10, 2011 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61160817 |
Mar 17, 2009 |
|
|
|
Current U.S.
Class: |
451/28 ;
451/344 |
Current CPC
Class: |
G02B 6/25 20130101; G02B
6/3863 20130101; B24B 19/226 20130101 |
Class at
Publication: |
451/28 ;
451/344 |
International
Class: |
B24B 1/00 20060101
B24B001/00; B24B 23/00 20060101 B24B023/00 |
Claims
1. A hand-held polishing apparatus for polishing an optical fiber
connector, the optical fiber connector including a connector
housing and a ferrule, comprising: a connector mount to receive and
hold the optical connector mounted on the end of an optical fiber
wherein the end face of the ferrule is adjacent to a polishing
media; a housing having an upper portion and a base portion; a
drive assembly to control orbital movement of the optical connector
and linear movement of the polishing media through the polishing
device; and a lubricant dispensing system to supply a lubricant
from an internal reservoir disposed with in the housing to the
polishing media near the end face of the ferrule of the optical
connector.
2. The polishing apparatus of claim 1, further comprising a spring
loaded pressure plate assembly to provide a contact force between
the polishing media and a terminal end of the optical fiber when
the optical connector is disposed in the connector mount
3. The polishing apparatus of claim 1, further comprising a
polishing media dispenser disposed within the housing that contains
a supply of tape style polishing media.
4. The polishing apparatus of claim 1, wherein the contact force is
from about 100 grams force to about 150 grams force.
5. The polishing apparatus of claim 1, wherein the connector is
held in the connector mount at a predetermined angle, the
predetermined angle providing for one of a flat polish that is
perpendicular to the longitudinal direction of the fiber and an
angled polish.
6. The polishing apparatus of claim 5, wherein the angled polish
comprises an angle from perpendicular of about 2.degree. to about
12.degree..
7. The polishing apparatus of claim 1, wherein the drive assembly
is string-activateable, wherein pulling on the string causes
optical connector to trace a polishing pattern of a known length
against the polishing media.
8. The polishing apparatus of claim 1, where in the optical fiber
connector is a multi-fiber optical fiber connector.
9. The polishing apparatus of claim 1, wherein the drive assembly
includes an electric motor, at least one battery, and a control
circuit.
10. A hand-held polishing apparatus for polishing an optical fiber
connector, the optical fiber connector including a connector
housing and a ferrule, comprising: a housing having an upper
portion and a base portion; a connector mount disposed within the
housing to receive and hold the optical connector mounted on the
end of an optical fiber wherein the end face of the ferrule is
adjacent to a tape-style polishing media; and a drive assembly to
control orbital movement of the optical connector and linear
movement of the polishing media through the polishing device.
11. The polishing apparatus of claim 10, further comprising a
lubricant dispensing system to supply a lubricant from an internal
reservoir disposed with in the housing to the polishing media near
the end face of the ferrule of the optical connector.
12. The polishing apparatus of claim 10, wherein the connector is
held in the connector mount at a predetermined angle, the
predetermined angle providing for one of a flat polish that is
perpendicular to the longitudinal direction of the fiber and an
angled polish.
13. A method of polishing an optical fiber connector comprising:
providing an optical fiber having a stripped terminal end;
inserting the fiber through a connector body and a ferrule, setting
a protrusion of the fiber tip from an end face of the ferrule;
securing the optical fiber in the optical connector; mounting the
optical fiber connector in a connector mount portion of a polishing
apparatus, the polishing apparatus including a housing having an
upper portion and a base portion, a drive assembly to control
orbital movement of the optical connector and linear movement of a
polishing media through the polishing device; and a lubricant
dispensing system; dispensing a lubricant using the lubricant
dispensing system to supply the lubricant from an internal
reservoir disposed with in the housing to the polishing media near
the end face of the ferrule of the optical connector; and
activating the drive assembly to polish the fiber tip protruding
from the end face of the ferrule.
14. The method of claim 13, further comprising cleaving an exposed
end of the optical fiber prior to setting the protrusion.
15. The method of claim 13, further comprising cleaving an exposed
end of the optical fiber after the optical fiber is secured in the
optical connector.
16. The method of claim 13, wherein the dispensing the lubricant
comprises the step of depressing an external flexible bulb to move
the lubricant from the reservoir.
17. The method of claim 13, wherein the activating the drive
assembly includes pulling a string to activate the drive assembly
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention is directed to an apparatus and method
for polishing an optical fiber, in particular, an optical fiber
terminated and polished in the field.
[0003] 2. Background
[0004] In the area of optical telecommunication networks, fiber
optic connectors are one of the primary ways to connect two or more
optical fibers. There are several classes of optical fiber
connectors including adhesive ferruled connectors, in which the
fiber tip is held in a substantially fixed position relative to the
tip of the ferrule by adhesively securing the fiber within the bore
of the ferrule. Another class of connectors includes non-ferrule
connectors, which rely on the buckling of a length of fiber to
create contact force. Another class of connectors includes remote
grip (ferruled) connectors, where the fiber is secured at some
distance away from the terminal end or tip of the fiber.
[0005] When installing a remote grip connector in the field, one
current practice uses a coplanar/flush polish. In remote grip
connectors, as with other connector types, low optical losses and
minimal reflections are achieved when the terminal ends of at least
two optical fibers make secure physical contact. However, any
differences in the coefficient of expansion between the fiber and
the ferrule assembly may result in a non-contacting fiber tip when
the temperature is raised, or lowered. The resulting gap can lead
to significant reflection. A conventional remote grip connector is
described in U.S. Pat. No. 5,408,558.
[0006] Another current practice involves a technician performing a
field polish to create a fiber terminal end which protrudes beyond
the ferrule tip. This method of polishing remote grip connectors
produces a range of protrusions that provide a secure physical
contact while avoiding excess force on the fiber tips. This method,
when carefully followed, allows sufficient physical contact of the
at least two fiber terminal end faces at temperatures for indoor
applications (0.degree. C. to 60.degree. C.). However, the
conventionally polished field-terminated remote grip connector may
not be recommended for outdoor use, which has more stringent
temperature requirements (-40.degree. C. to 80.degree. C.). Factors
leading to unacceptable optical loss may result from the intrinsic
variability of the field polishing process, craftsman error, over
polishing (e.g. using too much force or too many strokes and
coarse, clogged or contaminated abrasive) or substitution of a
different type of abrasive.
[0007] The following references describe conventional devices for
polishing optical fibers: US 2003/0139118 A1; US 2004/0086251 A1;
US 2008/0119111 A1; U.S. Pat. No. 3,975,865; U.S. Pat. No.
4,178,722; U.S. Pat. No. 4,291,502; U.S. Pat. No. 4,979,334; U.S.
Pat. No. 5,007,209; U.S. Pat. No. 5,185,966; U.S. Pat. No.
5,216,846; U.S. Pat. No. 5,349,784; and U.S. Pat. No.
5,351,445.
SUMMARY
[0008] According to an exemplary aspect of the present invention, a
hand-held polishing apparatus is provided for polishing an optical
fiber connector. The optical fiber connector includes a connector
housing and a ferrule. The optical connector is mounted on the end
of an optical fiber. The polishing apparatus includes a connector
mount to receive and hold the optical connector to position the end
face of the ferrule adjacent to a polishing media. The polishing
apparatus includes a housing having an upper portion and a base
portion, a drive assembly and a lubricant dispensing system. The
drive assembly controls orbital movement of the optical connector
and linear movement of the polishing media through the polishing
device, and the lubricant dispensing system supplies a lubricant
from an internal reservoir disposed within the housing to the
polishing media near the end face of the ferrule of the optical
connector.
[0009] In another exemplary aspect of the present invention, a
hand-held polishing apparatus is provided for polishing an optical
fiber connector which uses a tape-style polishing media. The
optical fiber connector, which is mounted on an end of an optical
fiber, includes a connector housing and a ferrule. The polishing
apparatus includes a connector mount to receive and hold the
optical connector to position the end face of the ferrule adjacent
to the tape-style polishing media. The polishing apparatus includes
a housing having an upper portion and a base portion and a drive
assembly. The drive assembly controls orbital movement of the
optical connector and linear movement of the tape-style polishing
media through the polishing device.
[0010] According to another exemplary aspect of the present
invention, a method of polishing an optical connector comprises
providing an optical fiber having a stripped terminal end. The
optical fiber is inserted through a connector body and a ferrule. A
protrusion of the fiber tip from an end face of the ferrule is set.
The optical fiber is secured in the optical connector. The optical
connector is mounted in a connector mount of a polishing apparatus.
The polishing apparatus includes a housing having an upper portion
and a base portion, a drive assembly and a lubricant dispensing
system. The method further includes dispensing a lubricant using
the lubricant dispensing system. The lubricant is supplied from an
internal reservoir disposed within the housing to the polishing
media near the end face of the ferrule of the optical connector.
Activation of the drive assembly initiates the polishing of the
fiber tip protruding from the end face of the ferrule. The drive
assembly controls orbital movement of the optical connector and
linear movement of the polishing media through the polishing device
causing the protruding fiber tip to travel a predetermined distance
against the polishing media. Further, the exposed fiber can be
cleaved either prior to setting the protrusion of the fiber from
the end face of the ferrule or after the fiber is secured in the
optical connector.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] The present invention will be further described with
reference to the accompanying drawings, wherein:
[0012] FIGS. 1A and 1B show two alternate isometric views of an
exemplary polishing apparatus according to an aspect of the present
invention.
[0013] FIG. 2A is a sectional view of an exemplary polishing
apparatus of FIG. 1A.
[0014] FIG. 2B is a cross-sectional view of an exemplary polishing
apparatus of FIG. 1A.
[0015] FIG. 3 is an exploded view of the drive assembly of an
exemplary polishing apparatus according to an aspect of the present
invention.
[0016] FIG. 4 is an isometric view showing a connector holder plate
disposed in an upper portion of the housing of an exemplary
polishing apparatus according to an aspect of the present
invention.
[0017] FIG. 5 is an isometric cut-away view showing the media
dispenser disposed in a base portion of the housing of an exemplary
polishing apparatus according to an aspect of the present
invention.
[0018] FIGS. 6A-6D is a top view showing how the orbital movement
of the connector holding plate results in the pivoting of the bell
crank which moves the polishing media in a linear direction.
[0019] FIG. 7 is a view of an exemplary polishing pattern according
to an aspect of the present invention.
[0020] FIG. 8 is an exploded view of an exemplary optical connector
which can be polished with the exemplary polishing apparatus of the
present invention.
[0021] While the invention is amenable to various modifications and
alternative forms, specifics thereof have been shown by way of
example in the drawings and will be described in detail. It should
be understood, however, that the intention is not to limit the
invention to the particular embodiments described. On the contrary,
the intention is to cover all modifications, equivalents, and
alternatives falling within the scope of the invention as defined
by the appended claims.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0022] In the following Detailed Description, reference is made to
the accompanying drawings, which form a part hereof, and in which
is shown by way of illustration specific embodiments in which the
invention may be practiced. In this regard, directional
terminology, such as "top," "bottom," "front," "back," "leading,"
"forward," "trailing," etc., is used with reference to the
orientation of the Figure(s) being described. Because components of
embodiments of the present invention can be positioned in a number
of different orientations, the directional terminology is used for
purposes of illustration and is in no way limiting. It is to be
understood that other embodiments may be utilized and structural or
logical changes may be made without departing from the scope of the
present invention. The following detailed description, therefore,
is not to be taken in a limiting sense, and the scope of the
present invention is defined by the appended claims.
[0023] The present invention is directed to an apparatus and method
for polishing an optical fiber terminated in an optical fiber
connector. As described herein, a simple method of field polishing
and assembly of an optical connector can provide consistent,
repeatable results and can substantially reduce the craft
sensitivity, when contrasted with traditional field polishing
methods, and can reduce connector installation costs. In a
preferred aspect, the polishing apparatus can be a lightweight,
hand-held, mechanical device that is operated manually in the
field.
[0024] FIGS. 1A and 1B show an exemplary polishing apparatus 100.
The polishing apparatus 100 includes a connector mount 120 and an
elongated housing 110 including a base portion 114 and an upper
portion 112 that can fit comfortably in one hand during the
polishing process. Within the housing, polishing apparatus includes
a drive assembly 150, lubricant dispensing system 130 and a media
dispenser 140 as shown in FIGS. 2A and 2B.
[0025] The upper and lower portions of the housing can be joined
together by known mechanical means such as by mechanical fasteners,
latches or clips. In the exemplary embodiment shown in FIGS. 1A and
1B, the upper and base portions 112, 114 of the housing may be
joined by placing four screws (not shown) through a tab 112a
extending from the upper portion 112 of the housing 110 and into a
threaded socket 114a on the base portion 114 of the housing wherein
the tab 112a is aligned with the threaded socket 114a when
assembled together. Alternatively, the upper portion and the lower
portion may be hingedly attached at the backside to facilitate
replacement of the polishing media and reduce the number of
mechanical fasteners needed to hold the upper portion of the
housing and the lower portion of the housing together.
[0026] The polisher housing 110 can be constructed from a rigid
material, such as a metal or a molded polymer (e.g., a glass or
mineral filled plastic). In a preferred aspect, apparatus 100 is
lightweight (e.g., less than 1 lbs., more preferably less than 0.5
lbs.) and can be held securely in one hand during operation.
[0027] In use, a connector 10 is inserted into the connector mount
120 of the polishing apparatus. A lubricant supplied by the
lubricant dispensing system 130 from an internal reservoir 132 can
be applied to the polishing media 142 near the connector tip. The
drive assembly 150 can be actuated to create the polishing motion
used to polish the end face of the fiber held by the optical
connector 10. The pattern 199 of the polishing motion is one in
which the optical connector moves in a circular orbit, represented
by arrow 199a, while the polishing media 142 moves in a generally
linear movement, represented by arrow 199b, and is shown in FIG.
7.
[0028] Referring to FIGS. 2-4, the drive assembly 150 is
responsible for controlling the orbital motion of the optical
connector and the linear motion of the polishing media during a
polishing operation. The drive assembly 150 can be disposed in the
upper portion 112 of the housing 110. The upper portion of the
housing can be divided into two chambers 115a and 115b by support
wall 112c. The first chamber 115a can have a lid or cover 112b to
allow access to the first chamber 115a for installation and/or
maintenance of the drive assembly components contained therein.
[0029] In an exemplary embodiment, the power to drive the polishing
mechanism can be provided by pulling on a string 151 attached to
drive assembly 150. String 151 is wrapped around a spool 152 within
the drive assembly which is attached to a first one way drive plate
153. A flat wound spring, not shown, retracts the string as the
user releases the tension on it causing it to wrap back around the
spool in preparation for the next polishing operation.
[0030] When assembled, wedge shaped projections 153a (FIG. 3) on
the first one way drive plate 153 engage with wedge shaped
projections 154a on a second one way drive plate 154. The drive
apparatus is mounted to a support wall 112c within the upper
portion 112 of polisher housing 114, such that when string 151 is
pulled, the second drive plate 154 and drive shaft 155 are rotated.
When the tension on the string is released, the mating wedge shaped
projections 153a, 154a of the first and second drive plates 153,
154 slip over one another. Thus, the second drive plate and drive
shaft do not rotate in a backwards direction when the spring is
released.
[0031] Drive shaft 155 passes through support wall 112c where it
connects to the center gear 156c in a three gear set 156. The three
gear set 156 includes the center gear 156c, a first side gear 156a
positioned on one side of the center gear and a second side gear
156b located on a second side of the center gear opposite the first
gear. In an exemplary embodiment, the first and second side gears
156a, 156b are the same size and turn in unison when the center
gear 156c rotates. Each of the first and second side gears has an
off-center stub 157a, 157b projecting from a lower side gear
surface as shown in FIGS. 2A and 3. These stubs 157a, 157b can
engage with receptacles 161a, 161b on connector holding plate 160
causing the connector mount 120 disposed on the connector holding
plate to move in an orbital motion. In an exemplary embodiment, the
diameter of the orbital motion can be about 0.5 in.
[0032] The motion of the connector holding plate 160 activates the
media dispenser 140 to mete out the polishing media 142 from a
storage roll 142a in a controlled manner. Media dispenser 140 may
be disposed within base portion 114 of the polisher housing 110 and
dispenses polishing media 142 as shown in FIGS. 2A and 2B. Media
dispenser 140 can include a container portion 141 to hold or
otherwise support roll 142a of polishing media 142. Alternatively,
the polishing apparatus can be configured to implement single-use
strips of polishing media.
[0033] Referring to FIG. 2A, the polishing media 142 can be in the
form of a strip. The strip can come in the form of a roll 142a
which will allow multiple polishing operations to be completed
before the roll needs to be replaced. Alternatively, the polishing
media comprises a single use strip which must be replaced each time
a new connector is polished. To simplify changing the polishing
media, the roll of polishing media may be held in a disposable
container. The polishing media may comprise an abrasive material
formed on a backing having a grit size from about 0.02 .mu.m to
about 2 .mu.m. Alternatively, the polishing media can include a
first course abrasive material for doing a course polish and a
second finer abrasive material for doing the final polish, each
occupying a particular section of the polishing media. The
polishing media selected can depend on a number of factors
including the application in which the connector will be used, the
type of finish needed, and the type of connector being polished. A
single media such as 2 .mu.m aluminum oxide could be used for
multimode connectors typically used in local area networks. Single
mode connectors with more stringent specifications may require
finer grit sizes or even multiple grit sizes of abrasive material
to obtain the necessary finish on the end of the fiber. The backing
can be formed from paper or a polymer film material such as a
polyester film. For example, the polyester film can have a
thickness of about 3 mil (0.08 mm). In an exemplary single mode
polishing process, a 0.02 .mu.m silicon dioxide abrasive on a 3 mil
polyester film (863XW 3M.TM. Final Polish, available from 3M
Company, St. Paul, Minn.) or a 0.05 .mu.m aluminum oxide abrasive
on a 3 mil polyester film (263XW 3M.TM. Lapping Film AO Type P,
also available from 3M Company, St. Paul, Minn.) can be used. While
in an exemplary multimode polishing process, a 2 .mu.m aluminum
oxide abrasive on a 2 mil polyester film backing (254X 3M.TM.
Lapping Film AO Type R3, available from 3M Company, St. Paul,
Minn.) can be used.
[0034] The roll of polishing media can be replaced by separating
the upper portion 112 and the base portion 114 of the housing 110.
The spent disposable container can be removed from the media
dispenser 140 and replaced with a new one including a roll 142a of
the appropriate polishing media 142. A length of the polishing
media 142 can be pulled out of the new container and routed over
spring loaded pressure plate assembly 149 before the upper portion
112 and the base portion 114 of the housing 110 are
reassembled.
[0035] Connector plate 160 interacts with tabs 143a, 143b on either
side of bell crank 143 causing the bell crank to pivot back and
forth as shown in FIGS. 5 and 6A-D. Bell crank 143 is pivotally
attached to a lower portion 114 of the housing 110 by pin 145. A
pawl 146 is attached to bell crank 143 on either side at points
146a, 146b. As the bell crank pivots to one side, one of the pawls
is pushed forward while the other is pulled back. When the pawl 146
is pulled back, a hook 146c on the end of the pawl engages with a
tooth on ratchet 147a on the side of a lower nip roller 147 which
causes the polishing media 142 to be meted out in a direction 148
when it is squeezed between the lower nip roller 147 and an upper
nip roller 147b (FIG. 2A) mounted in the upper portion 112 of
housing 110. As the bell crank pivots back in the opposite
direction, the forward pawl moves back and the rearward pawl on the
opposite side of the bell crank moves forward.
[0036] FIGS. 6A-6D show a more detailed view of how the movement of
the connector holding plate 160 causes the bell crank 143 to pivot
from side to side. FIG. 6A shows the connector holding plate
positioned in an arbitrary centered forward position relative to
the housing 110. As the gear set (not shown) rotates, the connector
holding plate 160 can move in a clockwise orbit as shown by the
trace of the polishing pattern 199 shown in FIG. 7. As the
connector plate rotates to the 3 o'clock position (FIG. 6B), the
connector holding plate 160 contacts tab 143b which extends from
one of the arms 143c of bell crank 143 causing it to pivot in a
direction 144b. As the connector holding plate 160 continues its
orbit through the 6 o'clock position (FIG. 6C) and to the 9 o'clock
position (FIG. 6D), the connector holding plate 160 contacts tab
143a which extends from the second arm 143d of bell crank 143
causing it to pivot in a direction 144a. The back and forth motion
of the bell crank results in the controlled meting out of the
polishing media as described previously.
[0037] During polishing, the polishing media 142 is supported by a
spring loaded pressure plate assembly 149 (see FIG. 2A) to assure
the proper contact force between the terminal end of the optical
fiber and the polishing media.
[0038] The spring loaded pressure plate assembly includes a
compliant layer 149a, a floating rigid base plate 149b, a hollow
support shaft 149e, a solid support shaft 149c and a spring 149d.
One end of the hollow support shaft 1493 is fixedly attached to the
rigid base plate 149b while the other end of the hollow support
shaft 149e is placed over a solid support shaft 149c that is
fixedly attached to the base portion 114 of the polisher housing
110. The outer diameter of solid support shaft 149c is slightly
smaller than the inner diameter of hollow support shaft 149e,
allowing hollow support shaft 149e, and therefore the rest of
spring loaded pressure plate assembly 149, to slide telescopically
up and down solid support shaft 149c. The spring 149d is sized such
that it fits over both support shafts 149c and 149e and is
constrained at its ends against rigid base plate 149b and base
portion 114, providing the lifting pressure for the spring loaded
pressure plate assembly 149. Compliant layer 149a can comprise a
relatively hard material (e.g., having a Shore A durometer of about
60 to about 80, preferably a Shore A durometer of about 70). The
spring force of the spring 149d provides overall compliance for the
spring loaded pressure plate assembly 149 while the compliant layer
149a provides the appropriate support for the polishing media
142.
[0039] In a further exemplary aspect, the appropriate contact force
on the fiber tip being polished can be from about 100 grams force
to about 150 grams force, preferably about 130 grams force,
depending on the length of the protruding fiber and the abrasive
media. The combination of contact force, compliance of the spring
loaded pressure plate assembly 149 and shape of the ferrule tip
cooperate to help provide a desired shape on the polished fiber
surface.
[0040] An additional feature of the dispenser system 140 is the
cut-off blade 197 (see FIG. 2A) provided on the polishing
apparatus. The cut-off blade 197 removes used portions of polishing
media between polishing operations.
[0041] An additional feature of the exemplary polishing system is
the integral lubricant dispensing system 130 housed within the
polishing apparatus. The lubricant dispensing system 130 can supply
a lubricant (not shown) to the polishing media 142 near the tip of
the optical connector ferrule. Referring to FIGS. 2A, 2B and 4, the
lubricant dispensing system 130 includes a reservoir 132 for
holding a supply of the desired lubricant, a flexible tube 133 to
guide the lubricant from the reservoir to the polishing media 142
and a pump 134 to deliver the lubricant. In an exemplary
embodiment, the reservoir 132 can be located in a rearward section
of the base portion 114 of the device housing 110. In an exemplary
embodiment the pump 134 can be a small positive displacement pump
such as a manually operated diaphragm pump, priming pump or plunger
pump. For example, FIG. 2B shows a bulb style priming pump 134
disposed in the polishing device 100. To use, the craftsman presses
on the external flexible bulb 134 on the outside of the device. The
compression of the bulb 134a moves the lubricant through a feed
tube 134b from the reservoir 132 to the polishing area through the
flexible tube 133. The lubricant can exit the flexible tube 133
through orifice 165 (see FIG. 4) to fill the fluid distribution
channels 166 adjacent the ferrule end face 15. Reservoir 132 has a
filling port capped off with a fill plug 135 in the wall of the
reservoir to accommodate easy filling of the reservoir with the
lubricant. In an exemplary aspect, the lubricant can comprise DI
water or another conventional polishing fluid.
[0042] As shown in FIG. 3, the connector mount 120 is disposed on
connector holding plate 160. Connector mount 120 is configured to
receive an optical fiber connector 10 therein. As described in
further detail below, once the optical fiber connector is fully
mounted in connector mount 120, the protruding fiber tip can be
polished by activating the drive assembly which controls the
polishing pattern that the tip of the ferrule traces on the
polishing media.
[0043] The connector mount 120 is configured to receive a
conventional optical fiber connector, such as an SC, LC, ST, FC or
MT style connector. For example, a conventional connector can
include a remote grip connector 10 (see e.g. FIG. 8). Such a
connector 10 is described in detail in US Patent Publication No.
2008/0226236, incorporated by reference herein in its entirety.
This exemplary connector 10 includes a fiber connector housing 312
and having an optical fiber terminated in the connector ferrule
332. When the optical fiber connector 10 is mounted in connector
mount 120, the mount is configured to bring the ferrule face 15 and
protruding fiber tip (not shown) into proximity of the polishing
media 142 which is supported by a spring loaded pressure plate
assembly 149. The connector mount 120 also secures the connector 10
in place to reduce potential movement caused by unintentional
forces placed on the fiber cable or connector components. The
structure of exemplary connector 10 and the polishing operation are
described in more detail below. The optical cable can be a
conventional cable such as a 250 .mu.m or 900 .mu.m buffer coated
fiber, Kevlar reinforced jacketed fiber, or other sheathed and
reinforced fibers.
[0044] In alternative aspects, the conventional connector 10 can
include a Crimplok.TM. Connector available from 3M Company (St.
Paul, Minn.), a 3M.TM. 8300 Hot Melt SC connector, or 3M.TM. 8206
FC/APC Connector (Epoxy) available from 3M Company (St. Paul,
Minn.). In an exemplary aspect, the connector 10 can have an SC
format. In other aspects, the polishing apparatus can be configured
to receive a connector having another standard connector format,
such as an LC format or an FC format. In a further alternative, the
connector mount 120 can be configured to receive a connector having
multiple fibers, such as an MT fiber connector.
[0045] The connector mount 120 is configured to releasably hold and
secure optical fiber connector 10 and to provide a snug fit to hold
connector 10, e.g., by a snap fit. Preferably, connector 10 can be
held by the connector mount 120 at a predetermined angle. For
example, the connector mount 120 can hold connector 10 for a flat
polish (0.degree.), where the polishing media is perpendicular to
the axial direction of the fiber, or, alternatively, an angled
polish that is at a small angle (about 2.degree. to about
12.degree.) from perpendicular, to yield an angle-polished
connector.
[0046] In an alternative aspect, the string pull of the drive
assembly can be replaced by a crank or a rotating knob. While in
another alternative aspect, the polishing apparatus manually
operated drive assembly can be replaced by an electric motor, at
least one battery, and a control circuit. The electric motor would
control the motion of the connector plate and the moving of the
polishing media during operation in a method similar to that
described above.
[0047] Advantageously, apparatus 100 can provide consistent,
repeatable polishing results and can substantially reduce the craft
sensitivity. The incorporation of the lubricant dispensing system
eliminates the need for an external supply of lubricant. Also, the
tape style polishing media allows the polishing apparatus to hold
enough media to polish a plurality of optical connectors before the
roll of media needs to be replaced, thus saving time and
simplifying the polishing process.
[0048] An exemplary method of the present invention provides a
repeatable process that can lead to repeatable field polishing or
optical fiber connectors. In particular, the following method can
be employed to effectuate one or more field polished optical fiber
connectors in a straightforward manner. In an exemplary aspect, the
overall process includes stripping and cleaving the fiber cable,
setting the fiber protrusion (distance between the fiber tip and
the ferrule end face, and polishing the fiber tip. After polishing,
the fiber tip can be cleaned.
[0049] In more detail, a strain relief boot (see FIG. 8, boot 380)
can be threaded onto the fiber cable onto which a remote grip-style
optical connector is being installed. For thicker fiber jackets
(e.g., 900 .mu.m fibers), an additional crimp sleeve (not shown)
can also be threaded onto the fiber prior to polishing. The
connector 10 may be seated in an installation tool or other holder
prior to cleaving. An appropriate length of optical fiber cable can
be prepared by removing a terminal portion (e.g., .about.6 mm) of
the cable jacket. The fiber can then be stripped of its buffer
coating using a conventional fiber cable stripper such that the
buffer coating extends about 0.5 inch beyond the cable jacket. The
exposed glass tip portion can be cleaned using an alcohol (or other
conventional cleaner) wipe.
[0050] The fiber can be positioned into a field cleaver, such as
the cleaver described in PCT publication Number WO2008/100768,
incorporated by reference herein in its entirety. A cleaving
operation, using e.g., a diamond coated wire, can be performed
using the field cleaver. This cleaver can produce a fiber tip
having a cleave angle of between 0.degree. to about 3.5.degree.
from perpendicular.
[0051] The cleaved fiber is then moved to a protrusion setting
mechanism that sets the distance the fiber tip protrudes from the
end face of the ferrule. At this stage, the fiber can be guided
into the remaining connector components until the fiber tip
protrudes from the ferrule end. In an exemplary aspect, the
protrusion setting mechanism comprises a setting jig having a
ferrule-type end with a fixed step formed thereon. The setting jig
is brought into contact with the connector 10 so that the stepped
end of the setting jig contacts the end of the connector ferrule.
This process sets the proper protrusion distance to the point where
a slight bow in the fiber assures that fiber contact with the
setting jig is maintained. A sufficient protrusion can be from
about 15 .mu.m to about 35 .mu.m, with a preferable protrusion of
about 25 .mu.m. With the remote grip connector, the gripping
element is then actuated using the actuator cap to secure the fiber
position. In addition, buffer strain relief is activated using the
buffer clamp portion of the connector 10. Optionally, when
utilized, a crimping tool can be used to compress the crimp sleeve
around the fiber jacket to secure the fiber cable in place after
the fiber protrusion setting.
[0052] In an alternative aspect of the invention the exposed end of
the optical fiber may be cleaved after the optical fiber is secured
in an optical connector, such as a Crimplok.TM. Connector available
from 3M Company (St. Paul, Minn.).
[0053] The connector 10 is thus ready for polishing and can be
inserted in connector mount 120 of the polishing apparatus 100. The
polishing media (e.g., a 863XW 3M.TM. Final Polish, available from
3M Company, St. Paul, Minn.) can be wetted with a lubricant (e.g.
DI water or other conventional polishing fluid) by pressing the
compressible bulb 134a (FIG. 2B) disposed on the polishing
apparatus 100 so that the pump will deliver the lubricant from the
reservoir 132 to the polishing media through an opening 165 (FIG.
4) in the connector holding plate 160 close the ferrule end face 15
of connector 10.
[0054] The craftsman can activate the polishing apparatus by
pulling on an end pull string 151. Advantageously, the pull string
can have a knob 151 a or other holder on an end thereof to
facilitate gripping the string during polisher activation. This
action activates the drive assembly 150 which creates moves the
connector holding plate 160 in an orbital motion while
simultaneously moving the polishing media in a linear direction. If
additional polishing is needed, this process can be repeated. The
degree of polish needed will determine the number of activation
steps needed to complete the polishing operation. Factors such as
the type of polishing media, connector style, and application need
to be considered when determining the required degree of polish
needed.
[0055] The exemplary embodiments described above can simplify the
field polishing process, while controlling several sources of
variability that have in the past led to a skill-level dominated
practice. For example, the common "air polishing" practice of
beginning a field polish while holding an abrasive polishing
material in air (without any controlled backing force being
applied) can be eliminated. Also, the field technician needs to be
concerned the polishing force or polishing distance (e.g. the size
and shape of figure 8's traced on the polishing media). The
polishing apparatus can be a simple hand tool, without the need for
a motor or power source. For certain connectors, such as described
above, only a single polishing step would be needed.
[0056] The present invention should not be considered limited to
the particular examples described above, but rather should be
understood to cover all aspects of the invention as fairly set out
in the attached claims. Various modifications, equivalent
processes, as well as numerous structures to which the present
invention may be applicable will be readily apparent to those of
skill in the art to which the present invention is directed upon
review of the present specification. The claims are intended to
cover such modifications and devices.
* * * * *